for power supply, difficult watt = better?

should i buy a power supply next to the highest watt? or should I first donate up the watts that my hardwares required first and decide?

for power supply, difficult watt = better?

It doesn't hurt to gain the higher wattage. Your power supply won't hold to work so hard, and that will hold internal heat down. I'm not sure roughly speaking your second question. Need some clarification.
I would be in motion with the cheapest and lowest watt you want, but if your running expensive hardware next to multiple good graphics cards next you should invest in I don`t know a more high expiration one... Also if your getting a cheap power supply you should get a power surge protected power fishing rod because supply's blow easy when theres a power surge especially the cheap ones
Don't try to make a payment up the watts. Because a 600W power supply does not actually supply 600W; it take 600W from the wall, converts it from AC to DC, then supplies the converted power to your components. It looses a unquestionable amount of power in the process, the amount is call the Power Correction Factor (PCF). Or you can use the term "efficiency" to represent how much power make it through to your components. A good newer power supply will hold an efficiency of in the region of 0.85. Also, this number will change depending on the exact amount of power it is drawing at the moment. It will own its peak success and a certain point. So a 600W power supply will supply only about 510W maximum to your components (assuming it's use at 100% load is 0.85).



So, the short answer is: Buy a GOOD QUALITY power supply beside more power than you think you'll entail. A cheap power supply will only make happen problems and burnt out hardware.